For generations, musicians from around the world have trekked to Chicago for a chance to play with the city's most revered living jazz artist – tenor saxophonist Von Freeman.

They gather Tuesday nights at the New Apartment Lounge, on East 75th Street, hoping the great Vonski (as everyone calls him) will invite them to the stage for a chorus or two.

But it turns out that all of Freeman's admirers around the globe – and all the reference books that detail his biography – have been wrong about a critical fact: Freeman's age. Moreover, Freeman himself has been mistaken about his true birth year, and even about the spelling of his name.

Check any musical reference work, and you'll see Freeman's birth date listed as Oct. 3, 1922, which would make him 88 years old. Some jazz dictionaries list his full name: Earl Lavon Freeman.

But the saxophonist's birth certificate, obtained by the Tribune, corrects the historical record, showing he was born Oct. 3, 1923, which means he's actually 87 years old. And the birth certificate shows that his first name is spelled "Earle," not "Earl."

None of this information in any way affects Freeman's position at the pinnacle of jazz in Chicago and around the globe. But because historical accuracy is essential to fully understanding an artist's life and work, every reference source on Freeman now will have to be fixed.

I had arrived early to cover the show Freeman was going to play with former Chicagoan Ed Petersen, another mighty tenor saxophonist. Just before the performance began, Freeman made a startling announcement. He told the folks sitting at the front of the room that he had discovered a note written by his late mother: It said he was a year older than he thought he was.

Immediately after the first set, I went up to the stage and asked Freeman to tell me more. He explained that the note said he was born in 1921, meaning he would turn 90 next October, a significant milestone not only for Freeman, but for Chicago jazz. The new birth date, Freeman joked, would help explain why his legs were killing him – he was almost 90!

Later, in a phone conversation, he fleshed out the contents of the message from his mother: "It was just her writing a note to tell me about 'the way you and your brother's age is misplaced. You were (born) 1921 and he was 1919,' " added Freeman, referring to his elder sibling, the late drummer Eldridge "Bruz" Freeman.

But Von Freeman's birth certificate, on file at the Cook County Clerk's office, tells a very different story: Freeman is actually a year younger than he thought, not a year older.

Why was Freeman's mother incorrect about his birth year?

"I never did get a chance to talk to her about this," Freeman said, noting that the document from his mother had recently disappeared amid piles of paper.

As for the spelling of his first name, Freeman says he always has used "Earl" and has no plans to change at this late date.

And though Freeman now knows he'll have to wait until 2013 to celebrate his 90th, he's not too perturbed about finding out his correct age.

"It really doesn't make any difference to me, one way or the other," said Freeman. "People have always classified me the wrong ways.

Von Freeman will be taking off this week from his regular engagement starting 10 p.m. Tuesdays at the New Apartment Lounge, 504 E. 75th St.; 773-483-7728.

South Loop Hotel concerts

Further details have emerged on the new concert series at the South Loop Hotel, 11 W. 26th St., honoring the legacy of Chicago saxophonist-clubowner Fred Anderson.

The events will be staged by the new Velvet Birdhouse Coalition and will start by featuring trumpeter Corey Wilkes, saxophonist Kevin Nabors, pianist Justin Dillard, bassist Christian Dillingham and drummer Isaiah Spencer, with doors opening at 9 p.m. and performance starting at 10 p.m. Jan. 21 in the hotel's L26 Restaurant and Lounge.

The Velvet Birdhouse Coalition, named for the Velvet Lounge and Birdhouse clubs that Anderson once operated, is supported by the Association for the Advancement of Creative Musicians (AACM), Asian Improv Arts Midwest, Jazz Institute of Chicago, Umbrella Music and various anonymous funders. They've joined forces in the wake of the Dec. 1 shuttering of Anderson's beloved club, the Velvet Lounge, at 67 E. Cermak Rd.

"This effort represents the collaboration and good will of Mr. Anderson's many personal friends and associates who worked alongside him for many years and who continue to owe him a debt of gratitude," said the coalition in a statement.

To read more from Howard Reich on jazz, go to chicagotribune.com/reich.